From 784261d830e76b71f2b42955a252330968bab8bb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20Lytek?= <michal.ly@wp.pl>
Date: Thu, 4 Apr 2019 21:58:58 +0200
Subject: [PATCH] feat(nullable): add support for setting defaultNullable
 option

wip: refactor name src
---
 src/helpers/types.ts           | 13 ++++++++++---
 src/schema/build-context.ts    | 10 ++++++++++
 src/schema/schema-generator.ts |  6 ++++--
 3 files changed, 24 insertions(+), 5 deletions(-)

diff --git a/src/helpers/types.ts b/src/helpers/types.ts
index 13713c423..8dc87d115 100644
--- a/src/helpers/types.ts
+++ b/src/helpers/types.ts
@@ -40,7 +40,8 @@ export function convertTypeIfScalar(type: any): GraphQLScalarType | undefined {
 export function wrapWithTypeOptions<T extends GraphQLType>(
   typeOwnerName: string,
   type: T,
-  typeOptions: TypeOptions = {},
+  typeOptions: TypeOptions,
+  nullableByDefault: boolean,
 ): T {
   if (
     !typeOptions.array &&
@@ -61,7 +62,11 @@ export function wrapWithTypeOptions<T extends GraphQLType>(
 
   let gqlType: GraphQLType = type;
   if (typeOptions.array) {
-    if (typeOptions.nullable === "items" || typeOptions.nullable === "itemsAndList") {
+    if (
+      typeOptions.nullable === "items" ||
+      typeOptions.nullable === "itemsAndList" ||
+      (typeOptions.nullable === undefined && nullableByDefault === true)
+    ) {
       gqlType = new GraphQLList(gqlType);
     } else {
       gqlType = new GraphQLList(new GraphQLNonNull(gqlType));
@@ -69,7 +74,9 @@ export function wrapWithTypeOptions<T extends GraphQLType>(
   }
   if (
     typeOptions.defaultValue === undefined &&
-    (!typeOptions.nullable || typeOptions.nullable === "items")
+    (typeOptions.nullable === false ||
+      (typeOptions.nullable === undefined && nullableByDefault === false) ||
+      typeOptions.nullable === "items")
   ) {
     gqlType = new GraphQLNonNull(gqlType);
   }
diff --git a/src/schema/build-context.ts b/src/schema/build-context.ts
index 4df39e863..a439efcbe 100644
--- a/src/schema/build-context.ts
+++ b/src/schema/build-context.ts
@@ -26,6 +26,10 @@ export interface BuildContextOptions {
   pubSub?: PubSubEngine | PubSubOptions;
   globalMiddlewares?: Array<Middleware<any>>;
   container?: ContainerType | ContainerGetter<any>;
+  /**
+   * Default value for type decorators, like `@Field({ nullable: true })`
+   */
+  nullableByDefault?: boolean;
 }
 
 export abstract class BuildContext {
@@ -37,6 +41,7 @@ export abstract class BuildContext {
   static pubSub: PubSubEngine;
   static globalMiddlewares: Array<Middleware<any>>;
   static container: IOCContainer;
+  static nullableByDefault: boolean;
 
   /**
    * Set static fields with current building context data
@@ -75,6 +80,10 @@ export abstract class BuildContext {
     }
 
     this.container = new IOCContainer(options.container);
+
+    if (options.nullableByDefault !== undefined) {
+      this.nullableByDefault = options.nullableByDefault;
+    }
   }
 
   /**
@@ -89,6 +98,7 @@ export abstract class BuildContext {
     this.pubSub = new PubSub();
     this.globalMiddlewares = [];
     this.container = new IOCContainer();
+    this.nullableByDefault = false;
   }
 }
 
diff --git a/src/schema/schema-generator.ts b/src/schema/schema-generator.ts
index 890a63e47..9c02be21c 100644
--- a/src/schema/schema-generator.ts
+++ b/src/schema/schema-generator.ts
@@ -543,7 +543,8 @@ export abstract class SchemaGenerator {
       throw new Error(`Cannot determine GraphQL output type for ${typeOwnerName}`!);
     }
 
-    return wrapWithTypeOptions(typeOwnerName, gqlType, typeOptions);
+    const { nullableByDefault } = BuildContext;
+    return wrapWithTypeOptions(typeOwnerName, gqlType, typeOptions, nullableByDefault);
   }
 
   private static getGraphQLInputType(
@@ -569,6 +570,7 @@ export abstract class SchemaGenerator {
       throw new Error(`Cannot determine GraphQL input type for ${typeOwnerName}`!);
     }
 
-    return wrapWithTypeOptions(typeOwnerName, gqlType, typeOptions);
+    const { nullableByDefault } = BuildContext;
+    return wrapWithTypeOptions(typeOwnerName, gqlType, typeOptions, nullableByDefault);
   }
 }